@rmdmoore This is why Jensen. You can get transformers from them that are only 1:4 or 1:8 which allow for greater bandwidth. There's no point in having more gain than you need since there are always performance tradeoffs to get the greater gain.
Step Up Transformer Question
Ok, so bear with me as this is new terrain for me. I was quite happy with how things were sounding and then I accidentally bumped the stylus of my Cadenza Black and snapped the cantilever clean off. I did some research and ultimately decided to have Steve at VAS at fix my cartridge but it was going to take a few weeks and there was going to be no way to play the Christmas vinyl that my wife loves so much. She told me to buy another cartridge so we could have Christmas records. I was stunned. I found a great deal on a Winfeld Ti on this site and pulled the trigger. I've got it on my table and it sounds amazing.
After speaking with Steve though, I'm going to trade in my Cadenza and have him build me a wood body cartridge to have something different. It will also be 0.2mv output. I think I've got the 2nd arm situation sorted (gonna buy a Wand and a pod to mount it on) which leaves the phono pre. I love my Rogers PA-2 and it is switchable between MC and MM with 2 different inputs in the back. Finally got the SUT part. I've been looking and trying to figure things out. I spoke with Roger and he said the transformer built into the PA-2 is 1:10 and with that I can achieve 70 or so dB of gain. I did a lot of reading and looking and while I'm sure a 4k+ SUT is amazing that's just not where I'm at with all the other expenses at the moment. I saw the Bellari MT502 was a stereophole recommended component for many years and Amazon had one on sale for like $349 or something. Figured can't hurt to try it, it's Amazon so I can always return it. I plugged it in with some admittedly questionable interconnects I had lying around and when I put the phono stage k there was a bit more hum than I'm used to but I said let's have a listen. Holy shit. This little thing blew my mind. Better impact, tighter bass, more space around instruments so better staging, improved transients. This puts me in an interesting place.
This is an extremely inexpensive piece and it has changed my system quite a bit. I think the little extra gain I get even at 1:12 brings the cartridge to life. My question is where do I go from here? Bob's makes the sky 30 which is switchable from 1:15 to 1:30 which I like because I can play with the gain tubes in my preamp and potentially go to a quieter 12au7 than the 12ax7 that's currently in there. Will that be a real improvement? Less hum? Had also considered ordering a Rothwell from jolly old England but can't find much on them. Thoughts? I'd like to keep this sub 1k or so for now. Maybe I'll save up for a big boy SUT later.
Showing 2 responses by atmasphere
@rmdmoore We've worked with SUTs a lot over the last 40 years. @lewm's suggestion of Jensen Transformers is an excellent one- they make some of the very best in the business at any price. One thing you learn very quickly is that you want the least amount of step up possible so as to work with your cartridge. The more step up you go for, the more issues the transformer can introduce. If you have 0.2mV you really only need 60-65 dB of gain if you have a regular line section in your preamp. So you should be using the MM input, not the LOMC input. The other thing that is tricky about SUTs is loading. The loading does not affect the cartridge (other than measurably and audibly limiting its high frequency bandwidth; lewm already linked to the thread on the Steve Hoffman forum that shows what is really going on), but loading is critical for any SUT! If the SUT is improperly loaded it will either 'ring' (distort, so adding brightness) or be rolled off if loaded too heavily. Jensen transformers has published a pdf file that shows the correct loading for their transformers when used with most known LOMC cartridges. Mot SUTs made for a specific cartridge are designed to be loaded at 47KOhms with 100pf of capacitive loading (which is about the capacitance of the tonearm cable 1 meter long); IOW they are designed to be plug and play. But if you use a different cartridge with such an SUT the loading will be off and it won't sound right! That is one reason I like to work with Jensen since they did their homework, figured out the loading values and so their transformers work with almost any cartridge. |